Android: Vertical ViewPager [closed]

Answer 1

Just an improvement on the answers from @Brett and @Salman666 to correctly transform coordinates (X,Y) into (Y,X) since device displays are rectangular:

...

/**
 * Swaps the X and Y coordinates of your touch event
 */
@Override
public boolean onTouchEvent(MotionEvent ev) {
    return super.onTouchEvent(swapXY(ev));
}

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    return super.onInterceptTouchEvent(swapXY(ev));
}

private MotionEvent swapXY(MotionEvent ev) {

    //Get display dimensions
    float displayWidth=this.getWidth();
    float displayHeight=this.getHeight();

    //Get current touch position
    float posX=ev.getX();
    float posY=ev.getY();

    //Transform (X,Y) into (Y,X) taking display dimensions into account
    float newPosX=(posY/displayHeight)*displayWidth;
    float newPosY=(1-posX/displayWidth)*displayHeight;

    //swap the x and y coords of the touch event
    ev.setLocation(newPosX, newPosY);

    return ev;
}

...

However, something still needs to be done to better the touchscreen responsiveness. The issue might be related to what @msdark commented on @Salman666's answer.

Answer 2

A currently more active repository is lsjwzh/RecyclerViewPager.

• last commit 12 Aug 2016, 16 Contributors, 1840 stars
• based on RecyclerView

Answer 3

This is A vertical scrollable ViewPager implementation.Works well with RecyclerView and ListView. guochong/VerticalViewPager.

use ViewPager.PageTransformer to make ViewPager scroll vertically, and also provide a View.OnTouchListener to deal with the scroll conflict.

/**
 * 1.dispatch ACTION_DOWN,ACTION_UP,ACTION_CANCEL to child<br>
 * 2.hack ACTION_MOVE
 *
 * @param v
 * @param e
 * @return
 */
@Override
public boolean onTouch(View v, MotionEvent e) {
    Log.i(TAG, "onTouchEvent " + ", action " + e.getAction() + ", e.rawY " + e.getRawY() + ",lastMotionY " + lastMotionY + ",downY " + downY);
    switch (e.getAction()) {
        case MotionEvent.ACTION_DOWN:
            downY = e.getRawY();
            break;
        case MotionEvent.ACTION_MOVE:

            if (downY == Float.MIN_VALUE && lastMotionY == Float.MIN_VALUE) {
                //not start from MOTION_DOWN, the child dispatch this first motion
                downY = e.getRawY();
                break;
            }

            float diff = e.getRawY() - (lastMotionY == Float.MIN_VALUE ? downY : lastMotionY);
            lastMotionY = e.getRawY();
            diff = diff / 2; //slow down viewpager scroll
            Log.e(TAG, "scrollX " + dummyViewPager.getScrollX() + ",basescrollX " + dummyViewPager.getBaseScrollX());

            if (dummyViewPager.getScrollX() != dummyViewPager.getBaseScrollX()) {
                if (fakeDragVp(v, e, diff)) return true;
            } else {
                if (ViewCompat.canScrollVertically(v, (-diff) > 0 ? 1 : -1)) {
                    Log.e(TAG, "scroll vertically  " + diff + ", move.lastMotionY " + e.getY());
                    break;
                } else {
                    dummyViewPager.beginFakeDrag();
                    fakeDragVp(v, e, diff);
                    adjustDownMotion(v, e);
                    return true;
                }
            }

            break;
        case MotionEvent.ACTION_UP:
        case MotionEvent.ACTION_CANCEL:
            if (dummyViewPager.isFakeDragging()) {
                try {
                    dummyViewPager.endFakeDrag();
                } catch (Exception e1) {
                    Log.e(TAG, "", e1);
                }
            }
            reset();
            break;
    }

    return false;
}

Answer 4

A slight extension this answer helped me to achieve my requirement (Vertical View Pager to animate similar like in Inshorts - News in 60 words)

public class VerticalViewPager extends ViewPager {

public VerticalViewPager(Context context) {
    super(context);
    init();
}

public VerticalViewPager(Context context, AttributeSet attrs) {
    super(context, attrs);
    init();
}

private void init() {
    // The majority of the magic happens here
    setPageTransformer(true, new VerticalPageTransformer());
    // The easiest way to get rid of the overscroll drawing that happens on the left and right
    setOverScrollMode(OVER_SCROLL_NEVER);
}

private class VerticalPageTransformer implements ViewPager.PageTransformer {
 private static final float MIN_SCALE = 0.75f;
    @Override
    public void transformPage(View view, float position) {

        if (position < -1) { // [-Infinity,-1)
            // This page is way off-screen to the left.
            view.setAlpha(0);

        }  else if (position <= 0) { // [-1,0]
            // Use the default slide transition when moving to the left page
            view.setAlpha(1);
            // Counteract the default slide transition
            view.setTranslationX(view.getWidth() * -position);

            //set Y position to swipe in from top
            float yPosition = position * view.getHeight();
            view.setTranslationY(yPosition);
            view.setScaleX(1);
            view.setScaleY(1);

        } else if (position <= 1) { // [0,1]
            view.setAlpha(1);

            // Counteract the default slide transition
            view.setTranslationX(view.getWidth() * -position);


            // Scale the page down (between MIN_SCALE and 1)
            float scaleFactor = MIN_SCALE
                    + (1 - MIN_SCALE) * (1 - Math.abs(position));
            view.setScaleX(scaleFactor);
            view.setScaleY(scaleFactor);

        } else { // (1,+Infinity]
            // This page is way off-screen to the right.
            view.setAlpha(0);
        }

    }

}

/**
 * Swaps the X and Y coordinates of your touch event.
 */
private MotionEvent swapXY(MotionEvent ev) {
    float width = getWidth();
    float height = getHeight();

    float newX = (ev.getY() / height) * width;
    float newY = (ev.getX() / width) * height;

    ev.setLocation(newX, newY);

    return ev;
}

@Override
public boolean onInterceptTouchEvent(MotionEvent ev){
    boolean intercepted = super.onInterceptTouchEvent(swapXY(ev));
    swapXY(ev); // return touch coordinates to original reference frame for any child views
    return intercepted;
}

@Override
public boolean onTouchEvent(MotionEvent ev) {
    return super.onTouchEvent(swapXY(ev));
}
}

I hope this might be helpful to someone else.

Answer 5

There's actually already one in the Android source. I've modified it to work better though:

package com.crnlgcs.sdk.widgets;



import android.content.Context;
import android.support.v4.view.ViewConfigurationCompat;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewParent;

public class VerticalViewPager extends ViewPager {
    private static final String TAG = "VerticalViewPager";
    private static final boolean DEBUG = true;

    private float mLastMotionX;
    private float mLastMotionY;
    private float mTouchSlop;
    private boolean mVerticalDrag;
    private boolean mHorizontalDrag;

    // Vertical transit page transformer
    private final ViewPager.PageTransformer mPageTransformer = new ViewPager.PageTransformer() {
        @Override
        public void transformPage(View view, float position) {
            final int pageWidth = view.getWidth();
            final int pageHeight = view.getHeight();
            if (position < -1) {
                // This page is way off-screen to the left.
                view.setAlpha(0);
            } else if (position <= 1) {
                view.setAlpha(1);
                // Counteract the default slide transition
                view.setTranslationX(pageWidth * -position);
                // set Y position to swipe in from top
                float yPosition = position * pageHeight;
                view.setTranslationY(yPosition);
            } else {
                // This page is way off-screen to the right.
                view.setAlpha(0);
            }
        }
    };

    public VerticalViewPager(Context context) {
        super(context, null);
    }

    public VerticalViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
        final ViewConfiguration configuration = ViewConfiguration.get(context);
        mTouchSlop = ViewConfigurationCompat.getScaledPagingTouchSlop(configuration);
        init();
    }

    private void init() {
        // Make page transit vertical
        setPageTransformer(true, mPageTransformer);
        // Get rid of the overscroll drawing that happens on the left and right (the ripple)
        setOverScrollMode(View.OVER_SCROLL_NEVER);
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {

        final float x = ev.getX();
        final float y = ev.getY();

        if (DEBUG) Log.v(TAG, "onTouchEvent " + x + ", " + y);

        switch (ev.getAction()) {
            case MotionEvent.ACTION_DOWN: {
                mLastMotionX = x;
                mLastMotionY = y;
                if (!super.onTouchEvent(ev))
                    return false;
                return verticalDrag(ev);
            }
            case MotionEvent.ACTION_MOVE: {
                final float xDiff = Math.abs(x - mLastMotionX);
                final float yDiff = Math.abs(y - mLastMotionY);
                if (!mHorizontalDrag && !mVerticalDrag) {
                    if (xDiff > mTouchSlop && xDiff > yDiff) { // Swiping left and right
                        mHorizontalDrag = true;
                    } else if (yDiff > mTouchSlop && yDiff > xDiff) { //Swiping up and down
                        mVerticalDrag = true;
                    }
                }
                if (mHorizontalDrag) {
                    return super.onTouchEvent(ev);
                } else if (mVerticalDrag) {
                    return verticalDrag(ev);
                }
            }
            case MotionEvent.ACTION_UP: {
                if (mHorizontalDrag) {
                    mHorizontalDrag = false;
                    return super.onTouchEvent(ev);
                }
                if (mVerticalDrag) {
                    mVerticalDrag = false;
                    return verticalDrag(ev);
                }
            }
        }
        // Set both flags to false in case user lifted finger in the parent view pager
        mHorizontalDrag = false;
        mVerticalDrag = false;

        return false;
    }


    private boolean verticalDrag(MotionEvent ev) {
        final float x = ev.getX();
        final float y = ev.getY();
        ev.setLocation(y, x);
        return super.onTouchEvent(ev);
    }
}

Answer 6

For someone who is struggling with how to make vertical ViewPager works inside horizontal, just do following stuff:

Vertical ViewPager

public class VerticalViewPager extends ViewPager {
    public VerticalViewPager(Context context) {
        super(context);
        init();
    }

    public VerticalViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    private void init() {
        setPageTransformer(true, new VerticalPageTransformer());
        setOverScrollMode(OVER_SCROLL_NEVER);
    }

    private class VerticalPageTransformer implements ViewPager.PageTransformer {

        @Override
        public void transformPage(View view, float position) {

            if (position < -1) {
                view.setAlpha(0);
            } else if (position <= 1) {
                view.setAlpha(1);

                view.setTranslationX(view.getWidth() * -position);

                float yPosition = position * view.getHeight();
                view.setTranslationY(yPosition);
            } else {
                view.setAlpha(0);
            }
        }
    }

    private MotionEvent swapXY(MotionEvent ev) {
        float width = getWidth();
        float height = getHeight();

        float newX = (ev.getY() / height) * width;
        float newY = (ev.getX() / width) * height;

        ev.setLocation(newX, newY);

        return ev;
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        boolean intercepted = super.onInterceptTouchEvent(swapXY(ev));
        swapXY(ev);
        return intercepted;
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        return super.onTouchEvent(swapXY(ev));
    }

}

Horizontal ViewPager

public class HorizontalViewPager extends ViewPager {
    private GestureDetector xScrollDetector;

    public HorizontalViewPager(Context context) {
        super(context);
    }

    public HorizontalViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
        xScrollDetector = new GestureDetector(getContext(), new XScrollDetector());
    }

    class XScrollDetector extends GestureDetector.SimpleOnGestureListener {
        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
            return Math.abs(distanceX) > Math.abs(distanceY);
        }
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        if (xScrollDetector.onTouchEvent(ev)) {
            super.onInterceptTouchEvent(ev);
            return true;
        }

        return super.onInterceptTouchEvent(ev);
    }

}